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so let's walk out to the front where we have all the pipes and so on that you bring the power into the building. look at all of this stuff. an acorn plant. >> a gutter connector. an unbelievable number of things. so here we are at a place where we have all of these big pipes. so let's walk over here. david, come with me here. what are we looking at here? what's going on? >> this is a metal conduit made out of aluminum. it's lightweight. that's the advantage. it's used for service conduits to take up the power from pg&e down to the meter. >> so on the outside of buildings sometimes you'll have the wires coming over from pg&e. >> the service drop. >> and i brought something called -- >> a weather head. >> weather head. here it is. >> so at the top you have the weather head. and the conductors come into the service drop. >> look at the front of the
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weather head. you see these little knockouts here. you knock it out and you run your service conductors. >> and the conductors go down the pipe. >> in san francisco we have special requirements for service entrance equipment because of the corrosive marine environment. right? >> that's correct. >> so what are some of our special local requirements? >> well, we require the conduit to either be aluminum rigid conduit or galvanized steel conduit. both of them, galvanized or aluminum, they are resis tonight corrosion. pg & e also has a rule, inch and a quarter minimum if they're going to attach the service drop to the conduit. because of that the standard minimum size is an inch and a quarter. >> ok. and that's typically necessary for any home, an inch and a quarter. >> in san francisco, yes. >> everybody is always saying that they want to have enough power to run all of their
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modern households. how much power typically does it take to run a household in our time? >> the proposed for single residence is 100 amps. unless you're using high-powered plineses that is more adequate for even a medium sized or even large house. when you start using electric cooking, electric heating, jacuzzis, steam, steam units, then you get up into a high use equipment. then your service has to increase to 125, 150 or 200. >> so you might have to step up to a bigger conduit >> as the service size gets bigger, the conduit gets bigger. >> and so what is this gie gigantic piece of equipment like? >> so this machine here. you brought the machine to cut. up to four inches. >> up to four inches you can cut it. >> cut and thread. >> and thread it as well.
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so you can take this solid pipe, thread it, fit it exactly. >> take the 10-foot piece. cut it shorter and thread it. >> we can cut and thread it. yeah. >> that's two inches. >> yeah, two inches. >> and you have a much bigger -- >> silver head. two inches. >> excellent. really good. and then here we have over here plastic. what do you use plastic for when you bring power into the building? >> that's not plastic. that's a nonmetallic rigid conduit. >> excuse me. it's not plastic but it's not metal. what is it? >> it's made out of p.v.c. and is suitable for underground for services and feeders and for pulling conductors in under the ground. >> i know in my neighborhood, in the inner sunset, we just had all of our utilities undergrounded so what used -- you know, one of these overhead service entrances is now underground that would have been the stuff that they switch it to. >> that's the cost effective method. >> excellent.
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>> when you put in a service, you also have to ground it. you connect it to the cold water pipe. you have to run supplementry round rods. this is a typical ground rod. it's actually seized in copper, a steel round rod with a copper coating. you have to drive it into the ground so that eight feet is in contact with the earth. >> one of the allowed methods of grounding. is that correct? >> for a single family residence that tiply is made only out of wood and has one water bite, you are required to supplement that water bipe a ground rod. >> how about if you use these other methods? >> if you have a concrete encased etec trode, pouring a footing and you have the opportunity to put the wire in the footing, you do not need the ground rod. >> so the code has a number of different ways you can provide grounding to a building. this is one. this is probably the most common method, except for new buildings where they actually bury the copper ground into the
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footing, into the concrete footing and attach it to the steel reinforcing part. this is one of the most common. but there are a lot of different ways that you can solve these problems. and the codes, not just the electrical codes but all the codes. give us different ways to deal with problem-solving. so this is a very common way. and then somehow we have to figure out how to connect this to the house so that severing ground in the house, so you don't get a shock when you touch stuff. >> we have an example of a small residential service, the combination meter sock yet. -- socket and disconnect. where you put 100 or 125-amp circuit breaker in here. the inch and the quarter pipe comes down on the top. typically this is mounted outside and you put the meter in. >> let's look down inside it here. so the power is coming down in the top it he's going down -- >> well it he's going down and terminates and pg &e puts the meter in. you take the wires out of the bottom. >> and go to disconnect. we will see in a minute else wrx -- elsewhere.
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what's this hole for over here? especially where the power is coming out. >> it could come out or you could seal this. >> or you could seal it. by the way, the cover parts, i can't have empty holes or you have mice and stuff live inning side your electrical equipment. >> that's correct. >> so this is for a typical house. this is 125 max. >> my guess will be 125-amp max. and this one is what we see for a big operation, like a restaurant or a commercial space. or even a multiple apartment building so here we have a six-gang meter sock eight ray. -- socket array. hold that there and here is where the power comes in. and here you can disconnect or connect the power, 400-amp power. the power would come from here over into our meter. what do you call this thing?
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>> i always call it the meter enclose you're. for example it might be suitable for five residential units and one board. would be the typical use for this piece of equipment. >> an interesting thing happening in the state of california right now. looking at six meters. many buildings have one meter, and yet for energy efficiency and for billing purposes, it helps to separate out the meter so you know how much each space is using. there's been a big issue about the so-called submeetering. we're going to see in a little while some new sub meetering equipment. but this is a method which is cost efficient because it allows each person to get their own bill. when you get your own bill, you know you want to keep your billow. where as if the rental unit came power and you don't pay a separate electrical bill, you might not be quite as careful. >> i believe the current public utilities commission code does require all individual
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residential units to be individually meters. that's for all new work. >> and for commercial, they allow separate submetering. ok. so we brought the power into the building. we're watching our fingers here. we have other ways we'll seat meters >> we have examples, a wide variety of metering and service equipment that can be chosen. the reason i wanted to show you this is to show you this new meter socket to allow the panel board to face the user in the garage and allow the meter reader to see it. >> excellent. why didn't somebody think of that before? >> i have no idea. there it is. >> little ideas that come to you in the middle of the night. so one of the things that david said is it's allowed to be used in san francisco. there's a really big piece of
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this whole puzzle about what equipment can be used x which is what is allowed and who decides what is allowed? so there are three stages to figuring out what is allowed. the first stage is something called testing, where somebody tests the piece of equipment to see if it meets some standard test requirement. astm or some other standard test requirement. then there's something called listing, the second part. where some listing agency, and the federal government approves listing agencies, has looked at all the test results and then issue as a report that says if this piece of equipment, whatever it is -- like this wonderful new connector -- is used -- >> cupeling. >> excuse me. is used in accordance with the following specific requirement, it will meet the requirements of the following. in other words, the listing says if you do it the right way, we can assure that you this will meet some standards. right? is that more or less correct? >> correct >> and the third part of that
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-- we have testing, listing. and then the third part is approval. and approval is something that's done at the local level here at the city of san francisco. we typically approve a listed product. like this kupling. occasionally we have somebody come forward saying, look, i have the listing. we say, that's great. but we don't allow to you use it here in san francisco. either the local law doesn't allow that kind of product or that kind of material, or we don't think it's safe. and i could give you some examples of that but basically 99% of the time we approve a list of products which has been tested, listed, and then approved by david or me. basically it's on behalf of the director of the department of building inspection. is that a good example? >> that's it. >> and day have i spends a lot of his time look at listings. tell us what this s. >> this is a cupling for electric metallic tubing.
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it's quite a large one. but the neat thing about this one is that it has a waterproof seal. it does not leak. this is a new advance in the industry. previously the fittings leaked and caused problems and now they're coming out with problems that don't leak. >> the codes require it be water -- >> the code requires all of these fittings outside subject to the rain be rain-proof. now the industries gradually are responding and providing rain-proof products. >> so my recollection is that we have damp proof and water proof. what is rain-proof? >> equipment can be suitable for use in a dry location. be suitable for use in the damp location or suitable in the wet location. the reason i say rain-proof is because the product standard and the code requires that the fittings for electric metallic
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tubing be capable of staying dry when they're south a spray of rain. >> i see. ok. i get it. >> and therefore suitable for use in the wet locations. >> wet locations. ok. good. interesting. who makes this, by the way? >> mr. loy? >> who makes this? >> american fittings. >> oh, yeah. e.m.t. only, four-inch, wet location. shows a little u.l. stamp on it. >> i have to add for the small fittings, when you can't put those marks on, you have to go to the box. it says it on the box. >> there's nonmetallic cable for you. it's the white stuff. and the yellow stuff. >> what's the dinches between white and yellow? >> white is 14-gauge wire.
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in san francisco, it's not used in commercials. the national code it's restricted to type five, wooden construction. >> this gauge up to 15 amp is used for your typical plug loads. >> this wire is used for the laundry, the circuits and the other slightly larger -- >> is there a piece sticking out here? it's noticeably bigger? >> no. not noticeably bigger. >> it has actually multiple conductors in it.
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three conductors >> three conductors. it's got a white conductor that's called the neutral. a black conductor that's called the ungroud grounded wire, hot wire. and it's got a conductor that's called the ground wire. >> let's take a-- it must take a lot of that wire in the house. >> yes, it does. here we have another wiring method. it's called electrical metallic tubing. it's a tubing that the wire is pulled in after the installation of the tubing versus the cable that i showed you before. >> so this is electrical metallic tubing. people call it e.m.t. it's a half-inch e.m.t. so you would put this in first and then pull the wire in later >> that's correct. >> it doesn't come prewired. >> this is to use a commercial application. and for fire alarm systems. >> but not typically in residential ices. >> not usually used in residential, wood frame construction. >> i see.
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>> look at this this is unbelievable. look at all the equipment you have. how can you have so much inventory? this must cost a fortune to stock all of this inventory. >> because, you know, doing contractor before. we know what you can use and what can you not use. so we know older equipment here, lots of contractors, they need it. and right away. >> so somebody who's come out of the industry as a contractor doesn't stock equipment that nobody's ever going to buy. he's stocking stuff people are gooding to come to buy. he knows exactly what they need to use. that's a very smart business strategy. excellent idea. you've got some metal conduit. what is that? >> it's a cable. it's metal-clad cable. it's a product used, our m.c. cable. metal clad cable, m.c. cable.
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it's what's used in commercial work. it's a tougher product. than the non-metallic cable. >> let's open it up and see what we got here. how many conductors? >> in this particular one there's four. >> show us what these conductors are. these are standards colors of different kinds of conductors. tell us what they are. >> let's start with the white conductor which is the grounded conductor or the neutral. the two hot wires are ungrounded conductors. the ones that will give you a shock. and the green one is the grounding conductor. it does not normally carry electricity. >> so the ground wire, or whatever you want to call it, is always green. is that right? that's right. >> and green may only be used for the grounding conductor and for no other color as white may only be used for the neutral or grounded conductor. and other colors may be used -- other colors other than white or green may be used. >> and those typically are black and red when you start. then if you have more
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conductors, you use other colors. but typically the red or the black. >> in the residences, it's black, black and red. and commercial work where you have 12208, it's black, red, blue. and if you go downtown, the 480 volts, it's brown, orange, yellow. boy. >> and one people with us today just asked a question. is there any reason why you can't wire the entire house with the heavier gauge wire rather than just the lighter gauge for the 15 amp circuits and the heavier gauge for the 20 amp cirçoyd, come up here and is there any reason why you can't wire it all with a heavier gauge wire? >> yes. because it's a 15 amp and the yellow is 20 amp. but some people are asking if they can use only yellow. you can do that >> you can overdo. you can't under do it. >> yes.
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>> some people want to save money and use 14 for 15 amp and there are limbs. >> and that raises an interesting points about the codes. the codes are actually a minimum standard. they're not a maximum standard. you can build many things way beyond the code. you can make things much better. the code tells you the lowest level it was acceptable for health and safety. >> yes. >> you have the wire that pull into the conduit, black, white. >> a minimum for a circuit, you would pull these two wires and a piece of v.m.t. or any conduit. back here, for the 480 volts, orange. >> right. and then we probably have some green here to ground this stuff someplace. >> hopefully we do. there it is. there it is. my goodness, show me that green.
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i want to see the green. there we go. there is our ground wire. it's interesting, the grounding is to important in buildings. everything has to be grounded and interestingly enough i remember reading years ago about hospitals and medical facilities, den at all offices and things, every single recentable needs an independent ground. >> it's called a redundant ground. speaking of which -- >> pull that out here. >> this is hospital grade m.c. cable. it's designed with two grounds and it's made for den at all care offices and -- den at all care offices and -- dental care offices and extra care rooms. >> extra care goes into these areas. what is the conductor made of in here? >> copper. >> copper is very valuable these days, right? and people strip out wire and sell it as copper to the
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recycling places i hear. >> that is stealing the copper because it is so high. so a lot of it outside, they're stealing copper. >> so do people come in and buy wire to replace what they stole? >> yes. >> oh, boy, what a terrible thing. here is a general duty safety switch. this is a nonfuse disconnect, right? disconnector connect? where would you have a thing like this? >> probably adjacent to the motor. >> you can lock it out when you turn the thing off. i can't close it. got my fingers in there. >> there some one with a fuse in there. >> there is a fuse disconnect. same thing but fuseable. i got my fingers caught too many times. they have another place where you can lock them out.
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as you turn it on or off, you can put a padlock through here or some other device. and when you're working on an electrical system, typically, you will lock it out. you will tag it out so that you know that the continuing is turned off and nobody -- thing is turned off and nobody continuation it on. you'll tag it out by put a tag. >> up until now, we have been talking about power wiring, 240 volts. here we are in some air where there is low-vot ago wiring used for communications. >> we have two kinds of wire. we have line voltage and low voltage. what is the difference between those two types. >> the low-voltage wiring doesn't present a shock hazard. you don't have to put the wires in a conduit or a cable. this is thermostat wire. it's called class two wire. when you have a class two
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transformer, you're allowed to run this cable either exposed or concealed in building construction without a cable. there would be an example of some similar. this would be computer wire and in a lot of new houses now that the people are putting the computer wire and telephone wires, as low as the thermostat wires in the walls and they don't have to use conduit or cable. all different colors. >> are there standards for what colors you use? is brown always used for thermostat wire? >> no code requirement. just a manufacturing requirement. all different colors. the only restriction that some jurisdictions do is they limit fire alarm cable to red. >> people have asked about insulation types, if you have heat blown through, you need higher-rated insulation? >> the general rule is you
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cannot put this kind of cable where environmental air is moving through. there is an exception in houses where you can go perpendicular to the space between a wood joys. there are different levels of fire resistance. the standard is it it can be just anywhere concealed, or exposed construction. the next standard is where it doesn't spread flames. you can put it in a shaft in a larger building. the highest redistance can go in another space used with environmental air where air is moving but not in a sheet metal duct. >> and many buildings have dropped ceilings and they run air in their dropped ceiling, and sometimes it's under floor. that has been this rated cable. >> it's required by code to be
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identified every 24 inches. you'll see the designation and it tells you as an inspector if it's appropriately installed. >> one of the big issues related to cabling and wiring is when a tenant moves out, they have to remove the low-voltage wiring. sometimes that's a serious problem. there is a lot of low-voltage wiring. >> the unused low-voltage wiring. they put that code in a number of years after there was a large fire in london that caused structural damage to a high-rise building due to the accumulation of come dustable materials. >> they have to have more wiring for computers and phones. if you cycle through, pretty soon you have an enormous amount of low-voltage wiring. >> that has been a problem in the past. we're trying to address it. >> great.
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>> one question we were just asked, if you want to get really clean power for home video, theater, or computer, how would you go about doing that? does it help to have better armored cable or how would you go about getting really clean power? >> that's a very complicated question. there are a lot of answers to it. one solution would to have a dedicated circuit, a kyr kit that comes from the panel board that only supplies the receptacles that you're going to be using for the computer or sensitive equipment is one answer. you want to make sure that you install that circuit, the wires are remote from any radio frequency devices or any other circuits that might impose a radio frequency on them. >> what kind of wires would
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impose a radio frequency? >> it could be a computer, another computer, it could be the microwave oven. >> you want to separate is from any other -- >> ideally. if you're running your wires in a raceway or an armored cable that uses ferrous metal, that protects those conductors against these radio frequencies much better than nonmetallic cable. that would be another strategy. and then if you're in a commercial installation where it is really, really important, you put in isolation transformers adjacent to the equipment. that's the most expensive solution but the best solution is to actually put an isolation device right at your equipment. they also have filters that you can buy, but that's a commercial-grade installation. residentially, a dedicated circuit, try to separate it from other wiring to the extent
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possible. >> anything you might want to add to that? >> yes, they're called a clean circuit. you use the m.c. cable or 12-three, 12-2, the whole circuit. the computer or the microwave. >> so if you can probably do it, it sounds like putting in some kind of metal conduit-clad cable or something that will really reduce the interference. read for me what all these little things mean here. let's tip it up a little bit. >> priority a.w.g. 6-3 type s.o.o. w 600 volt sunlight and water resistant. >> which means what? >> it means it's a cord rather than a cable or wire. the cord is not to be used for permanent wiring. this is a cord that is designed for temporary power. >> it's a big cord. >> it is, it's 50 amp.
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>> what do they mean when they say primary? >> i don't know what it means. american wire gauge, the six is the size of the aware, the 3 is the three conductors, the type s.o.o.w., that's extra hard use cord. the w stand for wet. 600 volts is the volts it's good for and in the sun and underwater. it's 90 degrees centigrade-rated. it can run as high as 180 degrees without deterioration. this can get really hot. >> what would you use this cord for? >> temporary power for construction. >> i see, ok. >> or you might use it for example, on a peer when you need a flexible wiring method to get from the shore to the pier. you are allowed to use cord wiring. >> it would be permanent -- >> it's an exception to the general rule. under certain conditions you
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can use cord and where flexibility is required, that's one example. >> ok. that is a completely category from all of these wires and cables that we see here. >> let's look at these wires and cables. this is armored. >> this is an armored cable. it has a single conductor in it and it is used for grounding. >> we see the copper without peeling it back, you can see the copper ground. >> sometimes you can use bare wire. >> this is bare wire, but it's solid. >> it's bare stranded wire. >> so we get wire that is stranded sometimes it's solid. >> here is an example of sod. so that these wires can be used for the same purpose. probably the same size installers prefer to use solid. it's required by code in swimming pools, but this is an easier, when it's stranded, it's easier to use. this is probably the cable of choice in concrete. this is the classic wire and n

February 25, 2013 8:00am-8:30am PST

TOPIC FREQUENCY San Francisco 6, Brown 2, M.c. 2, The 1, Fuseable 1, Den 1, U.l. 1, Astm 1, Pg & E 1, Etec 1, Red 1, Gooding 1, Priority 1, Us 1, London 1, Jacuzzis 1, The City 1, California 1, Mr. Loy 1
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